.footer{
    height: 120px;
    width: 100%;
    background-color: #888;
    color: #fff;
    text-align: center;
    padding-top: 50px;
}

.gundong-btn{
    width: 60px;
    height: 60px;
    position:fixed;
    right: 30px;
    bottom: 30px;
    opacity: 0;
}
.gundong-btn i{
    font-size: 60px;
}

